A head-up display apparatus has been known. The head-up display apparatus is configured to display an image such as driving information to be superimposed on an external landscape seen through a windshield of a vehicle (refer to Patent Literature 1, for example).
This head-up display apparatus includes inside a casing thereof an image display capable of displaying an image such as driving information, and an optical path forming member that guides the image displayed on the image display to a cabin. The optical path forming member includes at least a reflection mirror that reflects the image displayed on the image display.